Page Comparison

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C++	Blocks
Code Block language cpp theme Confluence while(a>0){ a = a-b; /* executed over and over until a<0 or a==0 */ }

To Do : Read up about for loop, do-while loop

Functions

• A function is a segment of code which can be invoked from different parts of the program in a parameterized manner
• A function involves 3 aspects
• Declaration (typically done in header files with extension .h)

int add(int,

int)

• Definition (typically done by the library vendor)

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int add(int x, int y){ // x, y are function 'parameters'

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                        //of the function 'add’

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  return x+y;

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}

• Usage (usually, we need to do only this)

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{
  … //other statements

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    c = add(a,b);

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/* causes add() to be called with a, b passed as arguments.

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    The value returned is assigned to c */
 
  … //other statements

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}

Note : Blocks do not allow you to declare or define functions explicitly. However, some built-in functions such as digitalWrite() can be called using appropriate blocks, as shown below.

{

  digitalWrite

C++	Blocks
Code Block language cpp theme Confluence {   digitalWrite(11, HIGH);

}

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Setup() and loop() functions

• Setup and loop are functions called automatically (unlike all other functions needs to be called explicitly)
• setup() is called once, when you release the reset button / plug in your Arduino / upload a new code onto the board
• loop() is called repeatedly; anything inside the loop() gets executed over and over as long as the system remains powered on

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Note : When using blocks, any setup code required is automatically inserted into setup(). The main program logic which implemented using blocks goes into loop().

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• Write detailed comments. This will be very useful later for you yourself or other people who read your code.
• Use descriptive variable names for variable etc. rather than short, generic names like i, j, k. This will help your code more readable and comprehensible.
• Indent your code properly. Indent with tabs, not with spaces. This also makes your code easier to read.
• Use constants/variables for values that appear at multiple places rather than hard-coding values.

void setup(){
    //setup code
}
void loop()
       {                // Poor position for opening brace.
    int j = 100;        // Non-descriptive variable name
  analogWrite(5, j);    /*  Indented with spaces, and not aligned with the previous line.
                            Hard-coded values.
                            No comment to indicate what the line does.*/
                }       // Poor position for closing brace.

const int leftMotor = 5; // pin 5 used to control left motor of the robot
void setup(){
    //setup code
}
void loop(){
    int leftMotorSpeed = 100;
    analogWrite(leftMotor, leftMotorSpeed); // to write the analog value 100 to pin 5.
}